LM4889 Datasheet, PDF (1/19 Pages) National Semiconductor (TI) – 1 Watt Audio Power Amplifier

June 2003
LM4889
1 Watt Audio Power Amplifier
General Description
The LM4889 is an audio power amplifier primarily designed
for demanding applications in mobile phones and other por-
table communication device applications. It is capable of
delivering 1 watt of continuous average power to an 8Ω BTL
load with less than 2% distortion (THD+N) from a 5V_DC
power supply.
Boomer audio power amplifiers were designed specifically to
provide high quality output power with a minimal amount of
external components. The LM4889 does not require output
coupling capacitors or bootstrap capacitors, and therefore is
ideally suited for mobile phone and other low voltage appli-
cations where minimal power consumption is a primary re-
quirement.
The LM4889 features a low-power consumption shutdown
mode, which is achieved by driving the shutdown pin with a
logic low. Additionally, the LM4889 features an internal ther-
mal shutdown protection mechanism.
The LM4889 contains advanced pop & click circuitry to
eliminate noise which would otherwise occur during turn-on
and turn-off transitions.
The LM4889 is unity-gain stable and can be configured by
external gain-setting resistors.
Key Specifications
j Improved PSRR at 217Hz, 5 - 3.3V
j Power Output at 5.0V & 2% THD
j Power Output at 3.3V & 1% THD
j Shutdown Current at 3.3 & 2.6V
75dB
1.0W(typ.)
400mW(typ.)
0.01µA(typ.)
Features
n Available in space-saving MSOP, SOIC, LLP, and micro
SMD packages
n Ultra low current shutdown mode (3.3 to 2.6V - 0.01µA)
n Can drive capacitive loads up to 500 pF
n Improved pop & click circuitry eliminates noises during
turn-on and turn-off transitions
n 2.2 - 5.5V operation
n No output coupling capacitors, snubber networks or
bootstrap capacitors required
n Unity-gain stable
n External gain configuration capability
Applications
n Mobile Phones
n PDAs
n Portable electronic devices
Typical Application
20035801
FIGURE 1. Typical Audio Amplifier Application Circuit
Boomer^® is a registered trademark of National Semiconductor Corporation.
© 2003 National Semiconductor Corporation DS200358
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